JPH04151837A - Etching equipment - Google Patents

Abstract

PURPOSE:To minimize the damage on a wafer and realize uniform etching, by arranging auxiliary rollers between main rollers and between the main roller and a pressing member, so as to be in parallel with each other and able to freely rotate. CONSTITUTION:Between main rollers A, B in a casing 1, between the main roller B and a retaining member 7, and between the retaining member 7 and the main roller A, the respective auxiliary rollers a-c are arranged so as to be in parallel with the main rollers A, B, and the retaining member 7 and able to freely rotated. As a result, at whatever angle position the orientation flat Wa of a wafer W may be situated, at least two points of the outer periphery of the wafer are retained by the main rollers A, B and/or the auxiliary rollers a-c. Thereby the movement of the wafer W in radial direction is blocked, so that the damage of the outer periphery of the wafer can be minimized. In addition, rotation irregularity of the wafer W can be prevented, and uniform etching is enabled.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an etching apparatus for etching the surfaces of a plurality of wafers by immersing them in an etching solution while supporting the wafers.

(Prior Art) Semiconductor wafers used as substrates for semiconductor devices are manufactured by slicing a single crystal ingot of silicon or the like at approximately right angles to the axis of the ingot, and then lapping, etching, and polishing the slices. It can be obtained by performing the following processing.

By the way, the etching process on the semiconductor wafer is performed by an etching device, or the etching device has at least two main rollers formed with a plurality of engagement grooves in the axial direction to support the wafer, and a plurality of engagement grooves formed in the same direction. A plurality of holding members formed in the axial direction are disposed in a drum frame-shaped casing parallel to each other and rotatable, and a drive mechanism is provided to rotationally drive the main roller.

By engaging one wafer in each of the engagement grooves formed in the main roller and presser member of the etching device and supporting it vertically, a large number of wafers can be placed in the casing at appropriate intervals. The casing and the wafer are then immersed in the etching solution in the bath. At this time, if the main roller is rotationally driven by the drive mechanism, all the wafers supported by the main roller rotate in the etching solution, and the surface of each wafer is uniformly etched.

(Problems to be Solved by the Invention) Generally speaking, semiconductor wafers have an orientation flat (hereinafter referred to as OF
When a semiconductor wafer having an OF formed thereon is etched using a conventional etching apparatus, the following problems occur.

In other words, each time the OF part of the semiconductor wafer comes into contact with the main roller, the semiconductor wafer moves in the radial direction within the casing, so the outer circumference of the wafer may be damaged by the impact or the rotation of the wafer may be uneven. Non-uniform etching may occur, resulting in a problem of poor wafer yield.

The present invention has been made in view of the above-mentioned problems, and its purpose is to prevent the radial movement of the wafer during rotation, thereby minimizing damage to the wafer, and to prevent uneven rotation of the wafer. An object of the present invention is to provide an etching device that can prevent the above-mentioned effects and enable uniform etching.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides at least two main rollers formed in plurality in the axial direction as retaining grooves for supporting the wafer, and a similar engaging groove. An etching device comprising a plurality of pressing members formed in the axial direction, arranged parallel to each other and rotatable in a ram frame-shaped casing, and including a drive mechanism for rotationally driving the main roller, The present invention is characterized in that auxiliary rollers rotationally driven by the drive mechanism are disposed in the casing between the main rollers and at appropriate angular positions between the main rollers and the pressing member so as to be parallel to each other and rotatable.

(Function) According to the present invention, even if the wafer has OF,
This is because the wafer is supported at at least two points on its outer periphery by the main roller and/or the auxiliary roller, regardless of the angular position of F.

The axial center of the wafer does not change, the radial movement of the wafer is prevented, the outer circumference is not damaged, uneven rotation of the wafer is prevented, and uniform etching is possible.

(Example) An example of the present invention will be described below based on the accompanying drawings.

FIG. 1 is a longitudinal cross-sectional view of the casing of the etching apparatus according to the present invention, FIG. 2 is an enlarged cross-sectional view taken along the line ■-■ in FIG. 1, and FIG. 3 is a view taken in the direction of the arrow ■-■ in FIG. , Figure 4 is I of Figure 3.
A sectional view taken along the line V-IV, and FIG. 5 is a schematic plan view of the etching apparatus.

In Fig. 1, reference numeral 3 denotes a casing made of polyvinyl chloride (PVC), which consists of side plates 2.2 at both ends and three support plates 3 disposed between these side plates 2, 2. are connected and integrated by three round reinforcing bars 4... to form a frame shape.

Then, the side plates 2, 2 and the support plate 3 of the casing l...
- Two main rollers A and B are inserted and supported in parallel and rotatably to each other, and these are arranged at angles α^ and α8 from the horizontal plane as shown in Fig. 2. There is. A plurality of link-shaped comb teeth 5 are formed on the outer periphery of each of the main rollers A and B in the axial direction, and between these plurality of comb teeth 5, there is a wafer W (see Fig. 2). ) is formed with an engaging groove 6 that is to be engaged with the outer periphery. As shown in FIG. 2, eight slits 5a are formed radially in each comb tooth 5, and the engagement grooves 6 communicate with each other via the slits 5a. ing.

Further, in the upper half of the casing l, at an angle α7 from the horizontal plane (see Fig. 2), a plate-shaped holding member 7 made of polyvinyl chloride is installed parallel to the main rollers A and B. As shown in FIG. 4, a plurality of comb teeth 8 are formed in the longitudinal direction on the inner side of the holding member 7, and the wafer is inserted between these comb teeth 8. Engagement grooves 9 to be engaged with the outer periphery of W are formed. In addition, the number and pitch of this engagement groove 9... are the main roller A,
The engagement grooves 6 are set to be the same as those of the engagement grooves 6 formed in B.

In this embodiment, as shown in FIG. 2, there are are auxiliary rollers a and b made of polyvinyl chloride, respectively.
, c are arranged parallel to the main rollers A, B and the pressing member 7, and are rotatable. Note that these auxiliary rollers a.

b, c and main rollers A, B are arranged so that their axes are located on approximately the same pitch circle, and auxiliary rollers a, b, c
are βa (=90°), βb, and β shown in Fig. 2. are placed at the angular positions of

On the other hand, as shown in FIG. 1, the side plate 2 of the casing l.
2 has a shaft 10.11 projecting horizontally, and a drive gear 12 and a center gear 13 are loosely fitted to one shaft 11 so as to freely rotate, and the center gear 13 is as shown in FIG. The roller gears 14 and 14 are connected to the ends of the main rollers A and H, and the roller gears 15 and 15 are connected to the ends of the auxiliary rollers a, b, and c.

The drive gear 12 meshes with a gear connected to an output shaft of a drive source (not shown) such as a motor. In addition, the drive gear 1
2. Center gear 13 and roller gears 14, 14.15
All materials are polyvinyl chloride (PVC)
has been adopted.

Next, an etching operation using the etching apparatus according to this embodiment will be explained.

First, a large number of sheets (in this example, 10
0 wafers W... are set, but prior to this setting, the auxiliary roller C or the side plate 2 of the casing L,
By removing a setting jig (not shown) provided at 2, the casing 1 is separated from the casing 1. Then, the wafer W
. The wafers W are vertically supported by being engaged with each other, and thus a large number of wafers W are housed and set in an orderly manner in the length direction at appropriate intervals within the casing L.

After that, when the auxiliary roller C is set to the original position using a setting jig, each wafer W is supported at four points at its outer peripheral edge by the main rollers A and B and the auxiliary rollers a and b, as shown in FIG. be done.

Note that a minute gap δ is formed between the outer peripheral portion of the wafer W and the auxiliary roller C.

In the above explanation, the auxiliary roller C is simply arranged to be detachably attached at the corresponding specific position of the setting jig, or the auxiliary roller C is installed along a guide groove (not shown) formed in the side plates 2, 2 of the casing 1. C may be rotated. Further, the support plate 3 may be a circular plate having the same outer diameter as the side plate 2.

The casing 1, in which a large number of wafers W... have been stored and set as described above, is immersed in the etching work housed in the tank 16 shown in FIG. Rotational power is input to the drive gear 12 from a drive source (not shown), and the drive gear 12 and center gear 13 are rotationally driven in a predetermined direction at a predetermined speed. Then, the rotation of these drive gear 12 and center gear 13 is transmitted to main roller A via roller gears 14, 14, 15, .
, B, and auxiliary rollers a, b, and c, which are each rotated in the direction of the arrow (counterclockwise) in FIG. 2, thereby causing all the wafers W to rotate in the same direction.

Incidentally, each wafer W is formed with an OF section Wa, but in this embodiment, the wafer W does not move in the radial direction no matter where it is located in the OF section wa, and its axis is fixed and does not change. This will be explained based on FIGS. 6 to 10. Incidentally, FIGS. 6 to 10 are views similar to FIG. 2 showing the state in which the wafer W is supported.

As shown in FIG. 6, when the OF part W of the wafer W comes to the position of the main roller A, the axis of the wafer W changes because it is supported by the auxiliary rollers a and C. do not.

Next, when the OF part wa of the wafer W comes to the position of the auxiliary roller a as shown in FIG. 7, the wafer W is supported by the main rollers A and B, so its axis changes. do not.

As shown in FIG. 8, when the OF portion Wa of the wafer W comes to the position of the main roller B, the axis of the wafer W does not change because it is supported by the auxiliary rollers a and b.

Also, when the OF part W of the wafer W comes to the position of the auxiliary roller b as shown in FIG. 9, the wafer W is supported by the main roller B and the auxiliary roller C, The heart does not change.

Furthermore, as shown in FIG. 10, when the wafer W comes to the position of the OF part Wa or the auxiliary roller C, the wafer W is supported by the main rollers A and B and the auxiliary rollers a and b, and the reaction heat is Due to the convection of the etching solution, the wafer W
Even if the wafer W tries to move upward, the movement of the wafer W is regulated by the auxiliary roller C, and the wafer W is slightly spaced by a clearance δ' between the OF part Wa and the auxiliary roller C (in this example, about 1 mm). Since only the height moves, its axis hardly changes. In this case, if another auxiliary roller d (not shown) is provided between auxiliary rollers b and c, the axis of the wafer W can be completely fixed.

As described above, no matter where the OF part Wa is located, the axis of the wafer W does not change and the wafer W does not move in the radial direction. , b, c, and damage caused by a strong collision can be avoided.

Furthermore, in this embodiment, as shown in FIG. 5, a bubbling device 17 is installed in the tank 16, and clean air bubbles are blown toward the casing 1 from the bubbling device 17. The etching liquid is stirred by the air bubbles, and the etching liquid tank 16
The temperature distribution within the wafer W becomes uniform, and the surface of the wafer W is etched uniformly, and deterioration of the etching solution is prevented.

Furthermore, in this embodiment, the comb teeth 5 of the main rollers A and B...
Since the radial slits 5a (see Fig. 2) are formed in the wafers W, the contact area with the comb teeth 5 of each wafer W is kept small, and the flow of the etching liquid near the outer periphery of the wafers W is suppressed. done smoothly.

(Effects of the Invention) As is clear from the above description, according to the present invention, at least two main rollers each having a plurality of engagement grooves formed in the axial direction for supporting a wafer, and a plurality of engagement grooves formed in the same direction, In the etching apparatus, the etching apparatus includes a plurality of holding members formed in the axial direction, which are rotatably arranged in parallel with each other in a drum frame-shaped casing, and a drive mechanism that rotationally drives the main roller. Since the auxiliary rollers rotated by the drive mechanism are disposed parallel to each other and rotatably at appropriate angular positions between the main rollers and between the main rollers and the presser member, the OF Regardless of the angular position, the wafer is supported at at least two points on its outer circumference by a main roller and/or an auxiliary roller, and radial movement of the wafer is prevented to minimize damage to the outer circumference. At the same time, uneven rotation of the wafer can be prevented and uniform etching can be achieved.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a casing of an etching apparatus according to the present invention, and FIG. 2 is an enlarged sectional view taken along the line ■-■ in FIG. Figure 4 is the ■ of Figure 3.
-IV line sectional view, FIG. 5 is a schematic plan view of the etching apparatus, and FIGS. 6 to 10 are views similar to FIG. 2 showing how the wafer is supported. DESCRIPTION OF SYMBOLS 1... Casing, 5... Comb teeth, 5a... Slit, 6.9... Engagement groove, 7... Pressing member, 16...
- Tank, 17... Bubbling device, A, B... Main roller, a. b, c-...Auxiliary roller patent applicant Shin-Etsu Semiconductor Co., Ltd.

Claims (3)

[Claims] (1) At least two main rollers each having a plurality of engagement grooves formed in the axial direction to support the wafer, and a holding member consisting of a plurality of similar engagement grooves formed in the axial direction in a drum frame-shaped casing. In the etching apparatus, the etching apparatus includes a drive mechanism that rotationally drives the main rollers, which are disposed parallel to each other and rotatable within the casing, and between the main rollers in the casing and between the main rollers and the presser member. An etching apparatus characterized in that auxiliary rollers rotatably driven by the drive mechanism are arranged at appropriate angular positions parallel to each other and rotatable. (2) The engagement grooves formed in the main roller communicate with each other in the axial direction of the main roller via slits formed radially in the comb teeth defining these engagement grooves. The etching apparatus according to claim 1. (3) The etching apparatus according to claim 1 or 2, further comprising a bubbling device that blows air bubbles toward the casing in a tank containing an etching solution in which the casing is immersed.